PAKTHENOGENETIC TKNDIONCY IN MKLANOCKRA MENIPFE. 269 



The Parthenogenetic Tendency in the Moth, 

 Melanocera menippe (Westwood). 



By 



Eriiof^t Warren, D.Sc.(L©nd.). 



Certain attempts have been made recently at tlie Natal 

 Museum to cross several species of Saturniid moths for the 

 purpose of investigating the relationships of hybrids to the 

 parents. It was hoped that if healthy hybrids could be raised 

 it might be possible to cross them among themselves and to 

 discover if any definite segregation of characters occurred. 

 The experiments were effectually closed in connection with 

 the species selected owing to the fact that crossing did not 

 readily occur, and no healthy offspring were secured. Never- . 

 theless, results of some interest were obtained. 



It was found that in one of the species, Melanocera 

 menippe ( Westivood) , there is a slight, but definite, tendency 

 for parthenogenesis. In this species there occurred some 

 indication of an increased parthenogenesis induced by the male 

 of another species. In a second case the male of one species 

 certainly appeared to influence the female of another, but it 

 was not possible to judge whether this was induced partheno- 

 genesis or incipient hybridism. 



Material. — In the Black Wattle (Acacia mollissima) 

 plantations of Natal the moth Gynanisa maia (Klug) is at 

 some seasons very abundant, and the caterpillar is capable of 

 doing considerable damage to the trees. During last season, 

 October, 1913, to March, 1914, the moth was very common in 

 the environs of Pietermaritzburg, and Mr. H. F. Pentland, 

 manager of the town wattle plantations, very kindly caused 

 about 130 pupa3 to be collected for me from the bases of the 

 trees. The pupa3 were obtained in the month of July. 



